Night-time time-lapse - sunsetF16.lua

I am just wondering why the exif info says only 15 seconds but the Iso is going up. Watching the camera im sure the exposure time was about 60 seconds.

AFAIK, the exif info in the JPG image does not always reflect the actual value used when CHDK overrides are applied. So observing the actual exposure is the only way to tell ( that and checking the resulting image actual exposure).